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Abstract Background Malaria is the parasitic disease with the highest global morbidity and mortality. According to estimates from the World Health Organization (WHO), there were around 249 million cases in 2022, with 3.4% occurring in Angola. The emergence and spread of drug-resistant Plasmodium falciparum have compromised anti-malarial efficacy and threatens malaria elimination campaigns using artemisinin-based combination therapy (ACT). Increased copy number (CNV) of the P. falciparum gene plasmepsin 2 (pfpm2) have been reported to confer parasite tolerance to piperaquine (PPQ) and the multidrug resistance-1 (pfmdr1), resistance to mefloquine (MEF) and decreased susceptibility to lumefantrine (LUM). PPQ, MEF and LUM are ACT partner drugs. Therefore, CNV detection is a useful tool to track ACT resistance risk. The potential for future treatment failure of artemisinin-based combinations (that include PPQ, LUM and AMQ), due to parasite resistance in the region, emphasizes the need for continued molecular surveillance. Methods One hundred and nine clinically derived samples were collected at Hospital Central Dr. António Agostinho Neto (HCL) in Lubango, Angola. qPCR targeting the small-subunit 18S rRNA gene was used to confirm P. falciparum infection. Copy number estimates were determined using a SYBR green-based quantitative PCR assay. Results Overall, this study revealed a low number of resistance CNVs present in the parasite population at Lubango, for the genes pfmdr1 and pfpm2. Of the 102 samples successfully analysed for pfpm2 10 (9.8%) carried increased CNV and 9/101 (8.9%) carried increased CNV of pfmdr1. Conclusions This study provides, for the first time, evidence for the presence of CNVs in the pfpm2 and pfmdr1 genes in P. falciparum isolates from southern Angola.

Abstract Background Anti-malarial drug resistance remains a major threat to global malaria control efforts. In Africa, Plasmodium falciparum remains susceptible to artemisinin-based combination therapy (ACT), but the emergence of resistant parasites in multiple countries in Southeast Asia and concerns over emergence and/or spread of resistant parasites in Africa warrants continuous monitoring. The World Health Organization recommends that surveillance for molecular markers of resistance be included within therapeutic efficacy studies (TES). The current study assessed molecular markers associated with resistance to Artemether−lumefantrine (AL) and Dihydroartemisinin−piperaquine (DP) from samples collected from children aged 6–59 months enrolled in a TES conducted in Siaya County, western Kenya from 2016 to 2017. Methods Three hundred and twenty-three samples collected pre-treatment (day-0) and 110 samples collected at the day of recurrent parasitaemia (up to day 42) were tested for the presence of drug resistance markers in the Pfk13 propeller domain, and the Pfmdr1 and Pfcrt genes by Sanger sequencing. Additionally, the Pfpm2 gene copy number was assessed by real-time polymerase chain reaction. Results No mutations previously associated with artemisinin resistance were detected in the Pfk13 propeller region. However, other non-synonymous mutations in the Pfk13 propeller region were detected. The most common mutation found on day-0 and at day of recurrence in the Pfmdr1 multidrug resistance marker was at codon 184F. Very few mutations were found in the Pfcrt marker (